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Tube amp with cheap transformers 'useless' ? - Page 3

post #31 of 106

1000

post #32 of 106
Thread Starter 

I thought the biggest factor in the cost of transformers was the cost of copper, a metal presumably in heavy demand in a wide variety of manufacturing processes as well as in the end products themselves ?? I know it's been heavily targeted by every scrap metal operation since WWII. 

post #33 of 106
Again, those products are sold through a dealer network, so in addition to the manufacturer markup, you have to add the dealer markup. So end user prices will be 25-40% higher. And a 20% GROSS margin (quite different from Net Profit) is decent but hardly impressive.
post #34 of 106

http://www.mennovanderveen.nl/nl/download/download_1.pdf points to steel lamination's possible distortion - at low signal levels

 

http://cinemag.biz/application_notes/AN-104.pdf - shows 80% Ni lam distortion is much better than Si-Fe - this is the higher level satuation related distortion


Edited by jcx - 8/9/12 at 11:02pm
post #35 of 106

Wow, two great and interesting articles. Thank you~ And of course, this is why they apply a high-frequency bias to tape recording heads, to swamp out the kink in the B-H curve. Totally makes sense. I stand corrected.

 

I'm going to try having an output transformer wound using the high nickel laminations to see if I can tell the difference, and how much it difference in cost. We'll see if I qualify as 'golden ears' Elliott.


Edited by elliottstudio - 8/9/12 at 11:40pm
post #36 of 106

Definitely an interesting discussion OP. Transformers are always a tough choice in the build process, and getting nice ones requires a high upfront cost. I'm sure it's one of the most sensitive cost areas for amp builders. As other posters have noted, high markup is a very necessary part of running a large business. When an amplifier needs a power transformer and two output transformers, and maybe even a choke or two, that is likely going to be the largest cost of the amplifier. If the manufacture is getting the transformers from another manufacturer (or overseas), the high cost of shipping is going to be even more of a concern. So if manufacturer A buys three $50 transformers in bulk from manufacturer B overseas and pays an extra $80 in shipping, then has to mark up as necessary, that might be a $700-900 cost on a $2000 amp. 

 

It's one of the many reasons I like to build my own equipment. Getting iron from manufactures directly allows you to afford nicer ones, like Transcendar, which are a very good value for the money. You don't need to go all out either, I've heard perfectly good sounding amps using Edcor iron, which is very affordable. 

post #37 of 106
Thread Starter 

Guys, I hope you'll indulge me further in this thread, as a discussion I had in Sound Science actually seems more relevant here. I got my wires crossed and misinterpreted something Steve Eddy said about Class A push-pull amps. I'm starting to get an insight into why well-designed tube amps, regardless of topology, are just as expensive as the 'glamour' SET amps. I'm currently leaning toward the  RWA Signature 15 on the basis that Vinnie has nearly taken all that nasty mains power out of the equation  biggrin.gif

 

 

 
Steve:
 
Depends on the amp. A typical push-pull tube amp when running in class A will draw a constant current from the power supply. However a typical solid state complimentary push pull amp running in class A will draw current from the power supply that's modulated by the signal. But if you take two of those complimentary push pull amps and bridge them together, when running in class A they will also draw a constant amount of current from the power supply.As for power conditioners and whatnot, that's another story. And although the amp may be drawing a constant current, the main reservoir caps in the power supply are still being drawn down and refreshed every 1/120th of a second so without regulation you'll still have power supply ripple on the supply rails. Just that by drawing a instant current, you won't end up with the signal on the supply leads (by way of their resistance and inductance) which can potentially feed back into the amplifier causing oscillation.
 
Germanium:
 
 Full "class A pushpull transformer coupled" tube amps, not  class A single ended or not class A transistor amps. The reason is that power is drawn from a single power supply rail that has a constant current that does not vary untill you get very close to going into class B & the grid starts to draw current. When one tube is drawing near max current in class A the other tube is drawing near nothing balancing the current drawn from the power supply. This does not happen in any other class A type amp other than push pull transformer coupled Class A tube amps.
 
Class A transistor amps almost always are direct coupled & have 2 rail power supplies, as a result even though the overall current is constant the current from each power supply rail is not constant but varies just like a class AB or class B amp.
 
Class A single ended amps have no opposite phase output tube to balance the current so even though the average power draw at full power is the same as at idle the current does vary with  the output of the amp at any given moment in time just like a class AB or class B amp.
 
Yes most class A transformer coupled push pull tube amp can be run just fine with no audible loss in qualty without power conditioners but I will say that most of these type amps already are very well conditioned internally already with pie filers that use 2 capacitors to ground & one 10 henry inductor in series between the two capacitors as well as between the rectifier & the amps output transformer. The inductor would cause problems in the sound of a Class B amp due to its resistance to varying current but since the current does not vary in a class A pushpull transformer coupled tube amp it has no audible effect on the sound  other than to reduce noise from the rectifier & line noise. This is as I said befor the power supply on said amps is not  in the signal path as there is 
no signal on the power supply on these amps untill you get very close to clipping.
 
Chrisj:
 
In ten words or less, NO.Running your amp Class A does nothing to reduce the effect of EMI/RFI, noise conducted down the power line or radiated noise.
 
Steve:
 
No, nothing Chris said is at odds with what what Germanium and me have said. It's only that it's a different issue. What I was addressing was your query about  amplifier topologies that draw a constant current from the power supply. What  Chris is talking about is noise getting into the system which can happen regardless of of whether or not the amp's drawing a continuous current from the power supply.
post #38 of 106
Quote:
Originally Posted by HiGHFLYiN9 View Post

high markup is a very necessary part of running a large business

 

 

You don't see many of those. Someone who can write but they can't read.

 

The excerpt I posted uses SEC report data to demonstrate that manufacturers can produce refrigerators at a markup of only 26% over cost.

 

These are not companies with small overheads. They have a chairman, board, managers, design engineers and production line workers. They have premises, tooling, power, warehousing and distribution, many of which a smaller company can do without.

 

A refrigerator is not that different from a tube amp. It has a pressed sheet chassis, iron cores, copper windings, a control system and interconnections. It connects to mains power. The complications that a tube amp has it makes up for in complications of its own. Bearings, tubing, a compressor, compression chamber, gas, a thermostat.

 

Even granting that there are substantial differences between a small tube amp manufacturer and a large refrigerator manufacturer, look at the bottom line.

 

Markups of 400% are being quoted as necessary against the 26% in the SEC data. SIXTEEN TIMES. It matters not one whit that exotic materials might be used in the construction of a transformer, because that is COST, not MARKUP.

 

I mentioned before the Grado RA-1. Not a tube amp, but still representative of what passes as acceptable in headphone electronics.

 

I don't object to paying a reasonable rate for people's labour, and even taking account of expertise, but the Grado RA-1 has a wooden box, 4 caps, 6 resistors, a switch, a potentiometer, 2 jack sockets and a $0.5 opamp. It retails at $450 depending on source. You can't tell me that that is necessary, and if it is, then the sooner Grado go out of business, the better as far as I'm concerned, because they're a sick (dysfunctional) business. They're a sick business in another sense, because even pricing the parts at $25, that's a 1800% markup. The damn thing should sell for $50, it's less sophisticated than an O2 by a long chalk and that's still twice what you'd pay for a Fiio.

 

This is the business ethic that characterises the headphone business, the water which all you fish cannot taste because you swim in it.

 

I don't care that you want to blow your hard (or not-so-hard in the case of tube amp manufacturers) earned on these items, but please, please, don't pretend that you are satisfying some economic necessity, all you're doing is enriching the unscrupulous in the mistaken belief that the cost of what you own somehow reflects on what what it can do for you, when everybody with an ounce of sense knows that even cheap electronic devices long since passed the point where they can be significantly distinguished by ear.

 

w

post #39 of 106
Thread Starter 

It's pretty well documented that the Grado amp is a wildly overpriced joke - I'm going to need more examples than that old dead horse. Granted, it does make you wonder what the markup on their phono cartridges is, but that's a whole other can of worms. I still look at cartridge prices with my jaw on the floor - clearly, the end result must warrant spending that much money. 

post #40 of 106
Quote:
Originally Posted by wakibaki View Post

Even granting that there are substantial differences between a small tube amp manufacturer and a large refrigerator manufacturer, look at the bottom line.

 

Markups of 400% are being quoted as necessary against the 26% in the SEC data. SIXTEEN TIMES. It matters not one whit that exotic materials might be used in the construction of a transformer, because that is COST, not MARKUP.

 

 

You are ignoring economy of scale. 

 

Despite a slim margin, many thousands of sales per year generates substantial cash flow. Did the refrigerator company include cost of MFR (man-hours, storage, and transport) in the raw cost of the refrigerator? You have not been so kind to include even minimum wage into the "cost" of an amplifier. 

 

Despite a large margin, relatively few sales per year generates little cash flow. If the MFR gets lucky and gets an extremely solid review maybe he will make a decent bit of money. 

 

Why do you ignore the efforts of the smaller company? If you consider the fact that the owner of the company is probably doing several jobs (design, material sourcing, construction, and sales in many small companies) he is doing the work of several people in the refrigerator company you mentioned. Considering the 2 hour rule he could easily be more productive than 4 salaries at the refrigerator place. And some schmuckfacehole would take the money he has fairly earned with hard work.

 

While there are certainly some amp MFR's who are making an absolute killing off of insane markups many of them are just eeking by.

Cables on the other hand are almost 100%BS.

 

Battery power supplies are a sad compromise compared to a well designed wall-supply. Sadly a well designed wall supply costs a lot and very few people take the time to hear the difference. 


Edited by nikongod - 8/14/12 at 7:03am
post #41 of 106
Cost of labor is very high on a phono cartridge. Those things are not easy to make - lots of very small, sensitive parts that must be perfectly aligned. Harder to manufacture than a tube headphone amp. The few somewhat big companies that make them, like Shure and Audio Technica, can sell very inexpensive ones (and they do) because they probably can do some actual machining on those. Most high end cartridges are built completely by hand, and it takes someone with considerable skill to do so.
post #42 of 106
Thread Starter 
Quote:
Originally Posted by Skylab View Post

Cost of labor is very high on a phono cartridge. Those things are not easy to make - lots of very small, sensitive parts that must be perfectly aligned. Harder to manufacture than a tube headphone amp. The few somewhat big companies that make them, like Shure and Audio Technica, can sell very inexpensive ones (and they do) because they probably can do some actual machining on those. Most high end cartridges are built completely by hand, and it takes someone with considerable skill to do so.

 

No argument, Rob, and I suspect that Grado were trying to capitalise on that whole 'handcrafted' ethos when they priced their headphone amp - surely they had to know it would backfire on them ? 

post #43 of 106
I suspect they were trying to capitalize on the fact that, considering the market, they were more likely to sell more, or at least as many, at the higher price. It's a funny thing, but many "markets" don't work how neoclassical economic theory would predict -- understanding a little psychology can go a long way.

As to the original topic of this thread, different transformer core materials can make a huge difference. However, not all materials are appropriate in all places. For instance, mu metal (nickel) has a much higher permeability and thus transfers a much higher fidelity signal. However, it also saturates more quickly than M6 due to DC. Thus, in order to build a mu metal cored OPT from nickel that will be used in a standard SET amp, the core must be made larger to accommodate the same signal level as a smaller M6 core. This larger core offsets any gains due to permeability and becomes more of a tone control than a fidelity increaser. Thus, in this case, it is not necessarily a better choice, though it is a much more expensive one.

In small signal applications with no DC, or even in parafeed, this same tradeoff is not as big of an issue. Thus, 600 ohm line level OPTs can be made from high nickel, and are of considerably higher quality than M6 equivalents. They are also small enough to not be prohibitively expensive. Indeed, in parafeed applications, not only can you use the higher fidelity core material, but you can also make the core smaller (even than an M6 SET OPT), both of which factors will increase fidelity. That said, in bulk quantities, nickel costs several times what M6 costs, so it still is not cheap.

Keep in mind that core material is but one variable. Audio transformers are extremely complicated devices, and how they are wound and stacked makes at least as much of an impact as the core.

And, if I may talk about my own amps for a moment, I often use amorphous cobalt core input transformers (from Lundahl). I think the benefits outweigh the costs (both in dollar terms, and in sound terms) but I recognize that many people would disagree. That's OK. For output transformers, I use high nickel (~80%) for solid state OPTs and low nickel (~50%) for tube parafeed. I have found these to work best in terms of sound and price considerations. None of these come cheap -- as a very small manufacturer I don't get much of a discount. So, for example, just the transformers (input + output) in the tube amp I make cost me more than the posted estimate of the cost to build a beyond reproach tube amp. Just buying the cores for the transformers would approach that estimate.
post #44 of 106
Quote:
Originally Posted by nikongod View Post

 

You are ignoring economy of scale. 

 

Despite a slim margin, many thousands of sales per year generates substantial cash flow. Did the refrigerator company include cost of MFR (man-hours, storage, and transport) in the raw cost of the refrigerator? You have not been so kind to include even minimum wage into the "cost" of an amplifier. 

 

It's gross margin, nikongod.

 

I'm not ignoring economies of scale, I don't expect a small company to operate at 26% gross margin, I expect maybe 4~8 times that.

 

I've got a design of my own with a parts cost of ~$100 I've considered marketing. Even hand building them myself I'd feel uncomfortable charging much more than $200, in fact I'd hope to come in a bit below that. Wouldn't you?

 

Quote:
Originally Posted by dsavitsk View Post

And, if I may talk about my own amps for a moment, I often use amorphous cobalt core input transformers (from Lundahl). I think the benefits outweigh the costs (both in dollar terms, and in sound terms) but I recognize that many people would disagree. That's OK. For output transformers, I use high nickel (~80%) for solid state OPTs and low nickel (~50%) for tube parafeed. I have found these to work best in terms of sound and price considerations. None of these come cheap -- as a very small manufacturer I don't get much of a discount. So, for example, just the transformers (input + output) in the tube amp I make cost me more than the posted estimate of the cost to build a beyond reproach tube amp. Just buying the cores for the transformers would approach that estimate.

 

We'll just have to disagree about what's necessary at the power levels involved in a headphone amp. It's your customers I disagree with really, I think they'd get more satisfaction buying an amp that isn't grossly overengineered (not a compliment) and giving the difference to a third world charity.

 

w

post #45 of 106
Thread Starter 
Quote:
Originally Posted by wakibaki View Post

We'll just have to disagree about what's necessary at the power levels involved in a headphone amp. It's your customers I disagree with really, I think they'd get more satisfaction buying an amp that isn't grossly overengineered (not a compliment) and giving the difference to a third world charity.

 

w

 

Harsh, and I cant see that it was called for. Like Justin's amps, consumers will either buy his amps or they wont. I agree that its nth degree stuff for a headphone amp, but clearly some people want that. 

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